Fluoro-alcohol terminated polycarbonates



Unite States This invention relates to new and improved polycarbonate resins. More particularly it relates to high molecular weight polycarbonate resins having exceptional chemical and thermal stability and ease of fabrication.

It is known that polycarbonate resins can be made which have exceptional strength and outstanding toughness. However, these resins are diflicult to fabricate from a melt thereof because they have very high viscosities at temperatures slightly above their melting points. It has been suggested that this difficulty can be overcome by fabricating high molecular weight polycarbonate resins at temperatures substantially above their melting points. When, however, a polycarbonate resin is heated to a temperature substantially above its melting point in order to fabricate it at a lower viscosity the polymer degrades and the resultant products have considerably reduced values for strength, toughness, heat resistance, transparency and other desirable properties.

It is among the objects of this invention to provide new and improved polycarbonate resins.

A further object of this invention is the provision of such polymers which can easily be fabricated from melts thereof into shaped articles.

A particular object of the present invention is the provision of high molecular weight polycarbonate resins which have exceptional thermal and chemical stability and have low melt viscosities.

Other objects and advantages of the present invention will be evident in the following description.

It has now been discovered that high molecular Weight polycarbonate resins having certain terminal groups on the polymer chains have improved properties, particularly low melt viscosity and unusually good thermal and chemical stability. According to the present invention polycarbonate resins having terminal groups obtainable by removing hydroxyl hydrogen from certain trihydrofi-uoroalcohols have low viscosities at temperatures above their melting points and very high thermal and chemical stability. Alcohols which form the chain terminators of this invention correspond to the formula in which n is a positive integer from 1 to 8 inclusive. Compounds suitable as chain terminators in accordance with the present invention are 1H, 1H, 3H-tetrafiuoro- 1-propanol, 1H, 1H, SH-octaiiuoro-l-pentanol, 1H, 1H, 7H-dodecafluoro-l-heptanol, 1H, 1H, 9H-hexadecafluorol-nonanol, 1H, 1H, 1lH-eicosafluoro-l-undecanol, 1H, 1H, l3H-tetracosafluoro-l-tridecanol, 1H, 1H, lH-octaco'safluoro-l-p'entadecanol and 1H, 1H, l7H-dotriacontafluoro-l-heptadecanol.

The carbonate polymers of the present invention are represented by the formula V in which O-A-O represents the divalent residue which can be obtained by the removal of hydroxyl hydrogens from an organic dihydroxy compound free of aliphatic unsaturation, T represents the monovalent residue which can be obtained by the removal of reactive hydrogen from a chain terminator of the present invention Patented May 22, 19%2 and m is a positive integer greater than 20 and preferably greater than 40.

The divalent residue can be obtained from a glycol such as ethylene glycol, tetramethylene glycol, hexamethylene glycol, 1,4-dihydroxycyclohexane, and decamethylene glycol. Preferably, however, the divalent residue is obtained from compounds represented by the formula HOArB-ArOH and forming polymers represented by the formula in which Ar and Ar are divalent benzene nuclei, that is, phenylene and substituted phenylene, and His a divalent aliphatic or cycloali-phatic radical, oxygen or sultonyl. Preferably, B is alkylidene or cycloalkylidene, that is, Ar and Ar are joined to the same carbon atom of the B radical. -Ar and Ar are preferably linked into the polymer chain at the 1 and 4 positions, the 4 positions being linked to B and the 1 positions being linked to oxygen in the polymer chain. When Ar and Ar" are further substituted, the substituents are preferably in the 2 and/or 6 positions. Illustrative examples of the B portion of the polymer in the above formula when B is alkylidene are methylene, ethylidene, propylidene, isopropylidene, 2,2 butylidene, 4-methyl-2,2-butylidene, and cyclohexylidene. Representative examples of Ar and Ar substituents are methyl, ethyl, isopropyl, Z-tertiary-butyl, phenyl and chloro.

The organic dihydroxy compound is preferably a diphenol, especially an alkylidene diphenol. Representative examples of alkylidene diphenols useable as a base material for making polycarbonate resins of this invention are 4,4'-isopropylideneorthocresol, 4,4-isopropylidenebis(2-phenylphenol) and 4,4-isopropylidene-bis(2,6- dichlorophenol). Other diphenols such as 4,4-sulfoxyldiphenol and 4,4'-oxydiphenol can be used in making the polymers of this invention. The organic dihydroxy compound nsed to make the chain terminated polycarbonate resins of this invention can be a pure compound or mixture of such compounds. T is a monovalent radical formed by the reaction of a chain terminator of this invention with an end group. When Ar and Ar are both 1,4-phenylene, the polymer has recurring units corresponding to the structure and when in addition B is isopropylidene, the polymer of this invention has a structure corresponding to the formula CH3 0 -j T in which T is a radical obtained from the chain terminator. Subscript m is a positive integer greater than 20 and preferably greater than 40.

The polymers of this invention can be made by modifying known techniques for making polycarbonate resins such as by the phosgenation of organic dihydroxyv cornpouncls or by the reaction of an organic dihydroxy compound with a bischloroformate, such modification com prising the addition of a chain terminator of this invention to the reaction mixture. 7

The following examples are illustrative of the invention but the invention is not limited thereto.

Example I To a solution of 250 grams of sodium hydroxide disminutes is very slight.

solved in 3 liters of water there are added with stirring, 570 grams of 4,4'-isopropylidenediphenol and 2.5 liters of methylene chloride. The resulting mixture is poured into a 10 liter three-mouthed flask. The flask and contents are placed in a constant temperature bath maintained at a temperature of between 26 C. and 27 C. The contents are stirred vigorously and phosgene gas is led into the flask below the surface of the liquid through a sintered glass tube until an end point at a pH of 7 is reached. To 1 part of the emulsion thus formed is added 2.5 mole percent, based on A part of the 4,4'-isopropylidenediphenol previously added, of 1H, 1H, 3H- tetrafluoro-l-propanol. There is then added a solution containing 75 milliliters of water, 9 grams of sodium hydroxide and 2 grams of 4,4-isopropylidenediphenol. Stirring is continued for 1 hour and l milliliter of a 65 percent aqueous solution of benzyltrimethylammonium chloride is then added as a catalyst. The resultant emulsion is again stirred until it separates into two layers. The supernatant Water is decanted and most of the methylene chloride is then volatilized by heating the solution. 'The viscous mass thus obtained is put on a glass plate,

oven at a temperature of between 110 C. and 120 C. The product is a dense solid polymer having a molecular weight over 10,000 and is stable at 340 C. (Unsatisfactory polycarbonate resins decompose or darken considerably at these temeperatures.) This chain terminated polycarbonate resin has a low melt viscosity at temperatures slightly above its melting point. The polymer obtained in this example has excellent chemical and thermal stability. I-ts viscosity decrease after being held at temperatures slightly in excess of its melting point 30 Example II The procedure of Example I is repeated using the same materials and proportions except that 2.5 mole percent, based on the 4,4-isopropylidenediphenol as in Example I, of 1H, 1H, SH-octafluoro-l-pentanol is substituted for the chain terminator of Example I. This only slightly less than the initial viscosity.

Example 111 To a solution of 230 grams of sodium hydroxide in 3 liters of water contained in a reactor are added with stirring, 570 grams of 4,4-isopropylidenediphenol and 2.5 liters of methylene chloride. The resulting liquid mixture is maintained at a temperature ,of between 26 C. and 27 C. The mixture is stirred vigorously and phosphene gas is fed into the reactor through a sintered glass tube situated below the liquid surface until the pH of the air dried overnight and then further dried in a vacuum liquid drops to 7. To' 0.1 part of the emulsion thus 7 formed are added 1 mole percent, based on 0.1 the amount of 4,4-isopropylidenediphenol previously added,

' v, of 1H, 1H, 7H-dodecafiuoro-lwheptanol, 9. grams of sodium hydroxide, and milliliters of water. vStirring is continued mechanically overnight. The material separates into two layers. The supernatant water. is decanted and methylene chloride is then volatilized by heating. The viscous mass thus obtained is put on a glass plate, air dried overnight and then further dried in a vacuum oven at a temperature of between C. and C.

The productis a dense, high molecular weight, polycarbq s r s having s lsnt ths mal' a d chemise s bility and a low melt viscosity. It can be fabricated into strong, tough films, filaments, and other shaped articles.

Examples IV T hrough VI The procedure of Example III is repeated using the same materials and proportions except that 2.5 mole percent based on the 4,4'-isopropylidenediphenol as used in Example III of one of each of the following materials is substituted for the chain terminator used therein: Example IV, 1H, 1H, 9H-hexadecafluoro-1-nonanol; 1H, 1H, 1lH-eicosafluoro-l-undecanol; Example VI, 1H, 1H, 17H-dotriacontafluorol-heptadecanol. The products are high molecular weight polycarbonate resins of outstanding thermal stability and have a low melt viscosity. Shaped articles can be made easily from their melts by injection molding, extrusion, casting, and other standard techniques.

The chain terminated polycarbonate resins of the present invention are characterized by high molecular weight, exceptional thermal stability and low melt viscosity. They can be mixed with dyes, delusterants, pigments, plasticizers, reinforcing materials and with other polymers. They are easily fabricated into useful articles such as films, fibers, sheets, tubes, rods and the like from a melt or solution thereof by conventional shaping techniques such as molding, casting, and extruding. also be used to make laminates, such as safety glass and as protective or decorative coatings.

That which is claimed is:

l. A high molecular weight, thermally stable polycarbonate resin terminated 'with a fluoro alcohol given by the formula H(CF CF CH OH in which n is a positive integer from 1 to 8.

2. A high molecular weight, thermally stable chain terminated polycarbonate resin according to claim 1 in which the fluoro alcohol is 1H, 1H, 3H-tetrafluoro-1- propanol.

3. A chain terminated polycarbonate resin having recurring units given by the structure in which the hexagons represent benzene rings and B is selected from the group consisting of a divalent hydro:

V carbon radical, oxygen, and snlfonyl, the chain ter'rninain which m is a positive integer greater than 40 and T is a radical formed by the removal of hydroxyl hydrogen from a fluoro alcohol corresponding to the formula H(CF --CF ),,CH OH in whichn is a positive integer from to 8. 7

References Cited in the file of this patent UNITED STATES PATENTS 1,921,756 Kienle Aug. 8, 1933 2,889,312 Szayna June 2, 1959 2,950,266 Goldblum Aug. 23, 1960 The resins can 

1. A HIGH MOLECULAR WEIGHT, THERMALLY STABLE POLYCARBONATE RESIN TERMINATED WITH A FLUORO ALCOHOL GIVEN BY THE FORMULA H(CF2-CF2)NCH2CH2OH IN WHICH N IS A POSITIVE INTEGER FROM 1 TO
 8. 